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Discussion Starter #1
i just put a crane 2031 in my 94 cobra and there is some valve noise now. here is what i put in:

-2031 cam
-matching valvesprings
-new motorsport lifters
-stock replacement pushrods

i also grinded the tips on the exhaust rockers to clear the retainers. my question is do i have to change the pushrods to longer ones? I hit past zero lash on all of them so i am completely confused. somebody please help me if you can. thanks in advance.

David
 

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I would measure the springs and the pushrods, chances are they sent you the wrong parts. Also, did you oil and pump up the lifters before installing them? If not,They(new lifters) will take some time to self lube after starting the engine.
 

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Discussion Starter #4
specs on the cam:

duration- 276/282*
lift- .513/.529

this is with 1.7 cobra rockers (bolt-down)

i set the spring height as close to the spec as possible. the spec is 1.940. they are a little tighter, maybe 1.930 or so. i primed the engine with a priming rod before i cranked it.
 

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276/282 is advertised duration, I'm guessing 218/220 @.050, that's a fairly mild cam. and the lift ,even with 1.7's should be ok. you shouldn't have any issues with the STOCK pushrods, did you compare the stockers with the OEM replacments that you are using? did you shim the rockers? use thicker head gaskets?I still say they sent you wrong parts.
 

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Discussion Starter #6
yup, i compared them. didnt mic them or anything, but held them next to each other. didnt shim the rockers or use thicker head gaskets. maybe the pushrods arent all exactly the same. they are sealed power brand, which i thought was fine. i should have checked preload while it was all apart, but i didnt. nothing was loose, so i assumed it was good.

hey, is it possible that a lifter isnt pumping up? b/c it doesnt sound like its coming from all of the valves. it actually sounds like it is coming from a concentrated area on bank 2. do lifters sometimes have to run for awhile to pump up?? i ran it for about 20-30 min tonight, and it seemed (might have been all in my head) to get a little quieter.

f this.
 

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it could also be an exhaust leak.......take a funnel with a tube on it, probe the motor with the tube while the funnel is near your ear to pin point the sound
 

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Discussion Starter #8
i am pretty sure its not an exhaust leak, but i guess it could be. i think i am gonna get me stethoscope out tomorrow and try to isolate the noise. if not i guess im ripping the valve covers off again to check preload:mad:
 

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read my reply above, you need to run the engine for a little while before the lifters will pump up/self lubricate. you could have a bad "new" lifter, I was under the impression from your previous post that you got the same reading on all of them(below zero valve lash), these are pedestal mount so, there is not a whole lot of room in adjusting the rockers. were you able to move the pushrods after adjustment? Sounds like you were trying to adjust these rocker arms like they were stud mount, if that's the case, do a search on here about pedestal mount rockers. I'm not trying to insult your intelligence, but we all make mistakes.
 

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Venomous do a search on 2031 cam installs on the corral archives, I know there is for sure in some cases when owners have installed the 2031 that there has been some pushrod issues, sounds like thats what U have. Check it out and I wouldnt let the car run to long, the lifters should pump up pretty quickly.
 

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I have a 2031 cam and ran into the problem of needing longer pushrods. From what I could tell, the 2031 is ground on a smaller base circle because the original cobra cam is a reground HO cam. This would explain why owners of 93, 94 and 95 cobra's usually have no problems reusing their stock pushrods and why non-cobra 5.0 car run into issues. I ended up getting crane cams pushrods then using .035 shim under the rocker pedestals.

As for noise, I have a lot of valvetrain noise. At first I thought it was because I had used a .025 and .035 shim, but even after reshimming, I still had some noticeable valve train noise. I yanked the valve covers and did some testing on the lifters (measuring how fast they leak down). I discovered 5 weak lifters which leak-down entirely too quickly (under 10 seconds). These lifters were brand new motorsport lifters (no warranty, how nice!) I havent replaced them yet. However, I did try a quick and dirty fix. I threw a 1/2 quart of ATF into the oil. While it did quiet a few of the lifters, they are still clacking.

Tony
 

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Discussion Starter #12
HAWK327 said:
read my reply above, you need to run the engine for a little while before the lifters will pump up/self lubricate. you could have a bad "new" lifter, I was under the impression from your previous post that you got the same reading on all of them(below zero valve lash), these are pedestal mount so, there is not a whole lot of room in adjusting the rockers. were you able to move the pushrods after adjustment? Sounds like you were trying to adjust these rocker arms like they were stud mount, if that's the case, do a search on here about pedestal mount rockers. I'm not trying to insult your intelligence, but we all make mistakes.
the way i "adjusted" them was to make sure they hit zero lash on the heel of the cam BEFORE i hit the required torque of 25 ft lbs on the pedestals. i didnt actually measure the preload with a dial indicator, but everything was tight.
 
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